Question

I’m using Propel 1.6.x and would like to be able to retrieve the connection name from a Propel Connection object. This is to facilitate the storage of an object in a singleton method, thus:

// If this is called twice with different connections,
// the second one will be wrong
protected function getHashProvider(PropelPDO $con)
{
    static $hashProvider;

    // Would like to use something like $con->getName() to
    // store each instantiation in a static array...
    if (!$hashProvider)
    {
        $hashProvider = Meshing_Utils::getPaths()->getHashProvider($con);
    }

    return $hashProvider;
}

Since a connection object is instantiated by providing a connection name (or accepting the default name) I’d have thought this would be stored in the object. But a cursory look through the code seems to indicate that it is only used to look up connection details, and is not itself stored.

Is there something I’ve missed, or should I submit it as a suggestion for Propel2? 🙂

Answer 1

Right, I’ve discovered that inside Propel, Propel::getConnection() doesn’t pass the name to the PropelPDO class at all, so there is no way it could contain what I need. Here’s how I’ve fixed it with that limitation in mind.

I’ve took the view that connections need to have a string identifier, so first I created a new class to wrap the connection:

class Meshing_Database_Connection extends PropelPDO
{
    protected $classId;

    public function __construct($dsn, $username = null, $password = null, $driver_options = array())
    {
        parent::__construct($dsn, $username, $password, $driver_options);
        $this->classId = md5(
            $dsn . ',' . $username . ',' . $password . ',' . implode(',', $driver_options)
        );
    }

    public function __toString()
    {
        return $this->classId;
    }
}

This gives every connection a string representation (to use it, I added a ‘classname’ key in my runtime XML). Next, I fix up the singleton, thus:

protected function getHashProvider(Meshing_Database_Connection $con)
{
    static $hashProviders = array();

    $key = (string) $con;
    if (!array_key_exists($key, $hashProviders))
    {
        $hashProviders[$key] = Meshing_Utils::getPaths()->getHashProvider($con);
    }

    return $hashProviders[$key];
}

Seems to work so far 🙂